Lung response to radiation: The time-course of post-radiation pulmonary edema and collagen deposition will be studied with a view to developing preventative treatment with inhibitors of microtubule assembly (e.g. colchicine). Hypothermia effect on microtubule assembly and cellular radiosensitivity will be studied in vivo and in vitro to evaluate the importance of microtubules in radiation responses. Spinal cord response to multifraction radiation will be studied to determine the capacity of this tissue for repair of sublethal radiation injury. Renal tubule response to multifraction radiation using a slow assay system for tubule cell survival will be studied.